If the Titan lake evaporated, how would the change in kinetic energy affect the speed of the molecules found in the lake? (highlight one)  The kinetic energy would increase. The molecules would move faster.
 The kinetic energy would decrease. The molecules would move slower.
 There would be no change in kinetic energy. The molecules would move at the same speed.

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.